Add a cross-platform alignment concept
Add a cross-platform alignment concept

[`alignof`](http://en.cppreference.com/w/cpp/language/alignof) has been present in MSVC since VS 2003, and [`alignas`](http://en.cppreference.com/w/cpp/language/alignas) has been present as `__declspec(align(n))` since the same date.  Because memory magic is going to be increasingly important for performance reasons in `AutoPacket`, provide alignment declaration in a cross-platform way with `AUTO_ALIGN` for use by downstream clients.

codemercenary/autowiring,codemercenary/autowiring,leapmotion/autowiring,leapmotion/autowiring,leapmotion/autowiring,leapmotion/autowiring,leapmotion/autowiring,leapmotion/autowiring,codemercenary/autowiring,codemercenary/autowiring,codemercenary/autowiring,codemercenary/autowiring